Gauge couplings of the Standard Model in the octonionic framework: invariant normalisations, a conditional weak-sector completion, and a scale-explicit matching ledger

We present a substantially revised gauge-sector account of the E8xE8 octonionic unification programme, superseding the earlier versions of this paper. The revision separates exact algebraic statements from results derived inside a stated effective model, and both from hypotheses about the microscopic trace dynamics. The number 3/8 is tied to the invariant half-spacing of the exceptional-Jordan family spectrum rather than to a convention-dependent norm, the length identification L_P^2/L^2=3/32 is removed from the gauge chain, and the exponential seed is reformulated as a multiplicative-character hypothesis. Inside a stated linear support model on the real ladder space H_6, colour invariance and the real Schur lemma force the photon profile to be proportional to the identity, so the dilution e^2/g^2=(3/8)(1/6)=1/16 becomes a theorem of that model; the colour matching g_3=g_star is downgraded to a hypothesis, since the same invariance criterion caps the linear-profile ratio at alpha_s/alpha_em=8, not 16. The spinorial weak-angle construction (sin^2 theta_W=0.2497) is withdrawn as a prediction via a normalisation no-go, and replaced by a normalisation-faithful two-channel completion. With Tr Q^2=16/3, Tr(T3)^2=2, Tr Y^2=10/3, equal-trace normalisation gives g_Y^2/g_2^2=3/5, and equal-kinetic diagonal locking of two abelian directions yields g_Y^2/g_2^2=3/10 and sin^2 theta_W=3/13=0.23077, which is 0.225% below the PDG value at M_Z (versus 8% high before); the data require the locking factor eta=0.5015, only 0.29% above equal locking. All comparisons run through explicit matching factors on the ledger d_3^2=1, d_2^2=13/48, d_Y^2=13/160, d_gamma^2=1/16. The mixed-regime comparison of alpha_em at Q=0 with alpha_s at M_Z is a phenomenological selection, not a derived RG statement; the same-scale benchmark misses the algebraic 16 by 6%.